In the novel, it was possible to preserve - somewhat - the life experience of people who had died. Their brains still maintained some level of activity; a "half-life" that could be perceived by the living.

Herbert made his way back to the cold-pac bins to search out number 3054039-B.

When he located the correct party he scrutinized the lading report attached. It gave only fifteen days of half-life remaining. Not very much, he reflected; automatically he pressed a portable protophason amplifier into the transparent plastic hull of the casket, tuned it, and listened at the proper frequency for indication of cephalic activity...

The customer seated himself facing the casket, which steamed in its envelope of cold-pac; he pressed an earphone against the side of his head and spoke firmly into the microphone: "Flora, dear, can you hear me?"